This invention relates to connectors for use in construction of buildings, highways, and other heavy structures, and more particularly to ductile chord connectors for use in connecting structural and reinforcing rods in construction, such as in precast concrete assemblies, as well as to connect the terminal ends of rods in and between any structures.
Typically, concrete structures include reinforcing elements, such as steel rods, commonly referred to as “rebar”. Increasingly, structures are being assembled using precast, reinforced (such as with metal reinforcing bar, also known as “rebar”) concrete modular assemblies. Such precast assemblies are typically connected to one another by embedding steel plates in the precast component and welding the adjacent embeds together when (or after) the precast pieces are installed next to each other. Existing embeds are fabricated from steel plates welded to rebar. These connections do not provide desirable flexibility and desired movement between and among the precast structures. For example, continuous precast highway bridge sections must be permitted to stretch while maintaining integrity under thermal variations as the precast elements expand and contract over the day and the year. Similarly, reinforced concrete and precast concrete building assemblies are subjected to wind sway, weight of building contents, and must also be able to move or bend while supporting the load. Additionally, naturally occurring forces, such as earthquakes, hurricanes, tornadoes, exacerbate the load forces on and between precast structure subassemblies. Known connection assemblies, such as the welded plate and rebar joint assemblies previously described herein, fail in a brittle manner in such conditions. Moreover, the failure of known connection assemblies inflicts undesired damage to the surrounding concrete, rebar and other components of concrete and precast concrete assemblies. Indeed, the variability in known connection assemblies, including the welding, weld plate, and rebar, as well as field assembly variability, makes the failure point of known connection assemblies unpredictable, uncontrolled, and even dangerous.
For all these reasons, there exists a continuing need for connectors for use in joining reinforced concrete assemblies, whether field cast or precast, as well as for connecting steel rods in any construction environment to overcome the disadvantages of the known prior art.